Cap for collapsible tubes



Patented Jan. 24, 1939 UNITED STATES PATENT OFFICE CAP FOR COLLAPSIBLETUBES Application June 12, 1937, Serial No. 147,849

2 Claims.

This invention relates to caps for containers and the like andparticularly to the screw caps for collapsible tubes.

Difficulty has been experienced in the past with collapsible tubes forthe reason that the usci' is apt to put the cap on the neck of the tubein slightly angular position instead of coaxially with the tube, withthe result that on screwing the cap into place, the threads on the stube neck, or sometimes even the internal threads of the cap are crossedand stripped. Another diiculty has been the accumulation inside of thecap and its threads of excess or unused pasty material exuding from thetube if such material ;f. is not entirely removed before the cap isscrewed My invention therefore contemplates the provision of pilot meanson the. cap to center and align the cap coaxially with the tubepreparatory to the engagement of the screw threads of the cap and neckthereby to insure the proper positioning and engagement of said threadswhen the cap is rotated and eliminating the danger of the threads beingstripped or crossed.

My invention further contemplates the provision of pilot means on thecap which not only automatically centers and aligns the cap on the neckof the tube, but also disposes of any excess pasty material at the endof the tube.

The various objects of the invention will be clear from the descriptionwhich follows and from the drawing, in which,

Fig. 1 is a partial elevation and partial vertical section of my new capas it appears applied to a tube preparatory to screwing it into place toseal the tube.

Fig. 2 is a similar view of the same showing the cap screwed into itstube-sealing position.

Fig. 3 is a similar view of a modied form of n the cap wherein the pilotmeans is made hollow.

In the practical embodiment of my invention which I have shown by way ofexample, the usual collapsible tube I0 is provided, on the reduced neckII of which are cut the external screw threads I 2. Said threadsterminate a considerable distance below the top surface I3 of the neckthereby providing a terminal cylindrical unthreaded surface.I4, thediameter of which is the same as that of the base of the threads I2. Thesealing cap 30 may be of any desired shape having a top portion and adepending skirt portion I5 and is provided with the annular recess I'Iconcentric with the skirt portion for the reception of the neck II ofthe tube. The outer 55 wall of said recess I'I is provided with theusual internal screw threads I6 adapted to lit and engage the threads I2of the neck.

Intergral with the top part of the cap and concentric with the skirtportion, is the pilot memben I9, the substantially cylindrical wall ofwhich forms the inner wall of the recess I1. The lowermost end part 20of said pilot member is preferably in the same plane as the lowermostedge 2I of the skirt portion of the cap, and is preferably roundedconvexly. The pilot member I 9 preferably tapers slightly to a somewhatgreaterdiameter at its upper end to permit the lowermost end thereof tobe readily inserted into the neck opening 22 of the tube. Adjacent itsuppermost end, that is, Where it joins the remainder of the cap, thepilot member is provided with an upwardly and outwardly tapered conicalsurface 23 merging with the top portion of the cap and adapted to engagethe circumferential edge 24 of the neck opening 22 and to seat thereonwhen the cap is screwed into place (Fig. 2) and thereby to seal saidopening.

To assemble the cap on the neck, the pilot member I9 is initiallyinserted into the neck opening 22 of the tube and at the same time thecap is moved downwardly to carry said pilot member as far into the neckas it will go. Said member I1 being very nearly of the same diameter asthat y of the neck opening, prevents any material tilting of the caprelatively tothe tube. At the same time, the internal threads I6 of theskirt portion of the cap slide over the unthreaded part I4 of the neckuntil they engage o-r contact with the uppermost of the threads I2. Whensuch Contact or engagement takes place, it must occur in the accuratelycentered position in which the cap is maintained and set by the pilotmember, whereafter rotation of said cap will screw the cap on to thetube in its proper position until the conical portion 23 engages theedge 24. It will be understood that when the pilot member I9 is firstfreely inserted into the neck opening, any pasty material which liesabove or adjacent the top of the neck opening is pushed back into thetube by said member, and is thereby prevented from reaching or passingout of the recess Il.

In that form of the invention shown in Fig. 3, the pilot member 30 ispreferably made hollow, being provided with a suitable preferablycentral recess as 3I. By the provision of said recess, it will beunderstood that less material is needed to form the cap, while at thesame time less resistance is oiered to the initial entrance of the pilotmember into the tube opening, since part of the pasty material at theend portion of the tube may enter said recess 3i.

It will be seen that by the provision of pilot means for guiding the capinto its proper initial position in which the threads thereof are readyto engage the corresponding threads of the neck, adequate means areprovided for insuring the proper positioning and sealing action of thecap on the tube even though it is attempted to assemble these parts moreor less carelessly.

While I have shown and described certain specific embodiments of myinvention, I do not Wish to be understood as limiting myself thereto,but intend to claim my invention as broadly as may be permitted by thestate of the prior art and the scope of the appended claims.

I claim:

1. In a one-piece closure cap, a top portion, an internally threadedskirt portion and a pilot member arranged inwardly of the skirt portion,said pilot member being hollow and depending from the top portion andhaving smooth inner and outer surfaces and terminating at its bottom insubstantially the same plane as the bottom of said skirt portion, saidpilot member having a top inner surface arranged below said top portionof the cap.

2. In a, one-piece closure cap, a top portion, an internally threadedskirt portion, and a pilot member concentric with and arranged inwardlyof the skirt portion, said pilot member being hollow and depending fromthe top portion and having smooth Unthreaded inner and outer surfaces.

GEORGE W. TEMPLE.

